<template>
  <div id="app">
    <main-top-bar></main-top-bar>
    <keep-alive>
      <router-view></router-view>
    </keep-alive>
    
  </div>
</template>

<script>
import MainTopBar from './components/common/TopBar/MainTopBar.vue'
import MainPage from './views/MainPage.vue'

export default {
  name: 'App',
  components: {
    MainTopBar,
    MainPage
  },
  created() {
    //在页面加载时读取sessionStorage里的状态信息
    if (sessionStorage.getItem("store") ) {
        this.$store.replaceState(Object.assign({}, this.$store.state,JSON.parse(sessionStorage.getItem("store"))))
    } 

    //在页面刷新时将vuex里的信息保存到sessionStorage里
    window.addEventListener("beforeunload",()=>{
        sessionStorage.setItem("store",JSON.stringify(this.$store.state))
    })
  }
}

</script>

<style>
 @import url("assets/css/base.css");

#app {
    background-color: #f5f5f5;
  }
</style>
